FABRICATION OF ALUMINIUM SURFACE COMPOSITE WITH FRICTION STIR PROCESSING (FSP) AND ITS CHARACTERIZATION

Abstract

Now a days, fabrication of metal matrix composites (MMCs) with improved mechanical properties and modified microstructures has attracted many attentions. One of the methods to produce MMCs is friction stir processing (FSP) which is a novel modifying technique. FSP is a method of changing the properties of metal through intense, localized plastic deformation. This deformation is produced by forcibly inserting a non-consumable tool into the work-piece, and revolving the tool in a stirring motion as it is pushed laterally through the work-piece. It comprises of a rotating tool with pin and shoulder which are inserted into a single piece of material and traversed along the desired path to cover the region of interest. Friction between the shoulder and work piece results in localized heating which raises the temperature of the material to the range where it is plastically deformed. During this process, severe plastic deformation occurs and due to thermal exposure of material, it results in a significant evolution in the local microstructure. The present work aims the fabrication of AA6061-T6 surface composite with reinforced layers of boron carbide (B4C), Silicon Carbide (SiC) and mixture of both through FSP. Microstructural characterization are performed through optical microscopy (OM) and scanning electron microscope (SEM). The effects of different reinforced particles are investigated on microstructure and micro hardness. Mechanical property such as tensile strength of specimen has been evaluated with and without reinforced particles by using friction stir processing. The tribological behavior such as wear on surface has been observed with Pin on Disc Tribometer. It has been observed that the micro hardness as well as hardness, wear rate and tensile strength of the MMC’s are found better by reinforcement with Boron Carbide during FSP.